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Richard J Jones

Publications and source records attributed to Richard J Jones.

At least 19 recordsLinked to original sources
PubMed2007

Use of T-cell antibodies for donor dosaging in a canine model of in utero hematopoietic stem cell transplantation.

AIM: Microchimerism following canine in utero hematopoietic stem cell transplantation (IUHSCT) development of T-cell dosing regimens. OBJECTIVE: To investigate the use of anti-T-cell antibodies for cell dosing of the donor graft in a canine model of IUHSCT. STUDY DESIGN: Canine IUHSCT was performed by ultrasound-guided intraperitoneal injection in days 35-38 of fetal canines with CD34(+) cells at doses of 4.5 x 10(8) to 1.3 x 10(9) cells/kg and T cells (CD3(+) CD5(+)) at doses of 8 x 10(6) to 8.8 x 10(8) cells/kg. Postnatal studies included tissue histology and polymerase chain reaction-based chimerism analysis. RESULTS: Term survival was 86-100%. Microchimerism (0-2%) was detected in five of eight recipients in multiple tissues. Histopathology revealed no evidence of graft-versus-host disease (GVHD). CONCLUSION: Canine IUHSCT is a useful model to investigate the role of donor T cells in engraftment and GVHD. IUHSCT at early gestational ages with high doses of donor T cells in the graft yields microchimerism in multiple tissues without GVHD.

Animals↗
PubMed2007

Integrating PET and PET/CT into the risk-adapted therapy of lymphoma.

UNLABELLED: Imaging with 18F-FDG PET is increasingly accepted as a valuable tool for lymphoma management. A recent shift in the use of PET and PET/CT in medical practice has become evident. We selected aggressive lymphomas as a platform for the discussion of these imaging modalities in oncology patients and the resulting management questions. METHODS: On the basis of our clinical experience and a review of the literature, we evaluated the emerging role of 18F-FDG PET in staging, response assessment, risk stratification, and tailored therapy. We explored the biologic meaning of true-positive or true-negative PET results in assessing tumor killing and the implications for risk-adapted therapy of lymphoma. RESULTS: PET/CT improves the accuracy of staging and response assessment over that of conventional anatomic imaging. The strong prognostic value of PET for aggressive lymphomas is established, whether the imaging is performed at the end of therapy or after only a few cycles of chemotherapy. How to modify therapy on the basis of PET results is not yet established, although it is clear that high-risk patient subsets can be reliably identified. CONCLUSION: PET/CT improves the accuracy of staging and response assessment over that of CT alone. A negative midtreatment PET result does not indicate the absence of a viable tumor or that therapy can be abbreviated or reduced in intensity. Similarly, a positive PET result does not necessarily indicate a viable tumor or that extending or intensifying treatment will benefit the patient. In assessing response, it is possible that prognosis rests not only on whether the PET result is positive or negative but also on the intensity of the signal. Although the prognostic value of PET for lymphoma is now clear, how to tailor therapy accordingly is a separate matter that requires further investigation.

Fluorodeoxyglucose F18↗
PubMed2006

Strategies to eliminate cancer stem cells: clinical implications.

Over the past two decades, major advances in our understanding of cancer have translated into only modest increments in survival for the majority of cancer patients. Recent data suggesting cancers arise from rare self-renewing stem cells that are biologically distinct from their more numerous differentiated progeny may explain this paradox. Current anticancer therapies have been developed to decrease the bulk of the tumour mass (i.e. the differentiated cancer cells). Although treatments directed against the bulk of the cancer may produce dramatic responses, they are unlikely to result in long-term remissions if the rare cancer stem cells are also not targeted. Conversely, treatments that selectively attack cancer stem cells will not immediately eliminate the differentiated cancer cells, and might therefore be prematurely abandoned if clinical activity is judged solely by traditional response criteria that reflect changes in the bulk of the tumour. Re-examining both our pre-clinical and clinical drug development paradigms to include the cancer stem cell concept has the potential to revolutionize the treatment of many cancers.

Antineoplastic Agents↗
PubMed2006

Graft-versus-host reactions and the effectiveness of donor lymphocyte infusions.

We retrospectively analyzed 83 consecutive recipients of donor lymphocyte infusions (DLI) after allogeneic transplantation for factors associated with disease response and graft-versus-host disease (GVHD). DLI was highly effective in relapsed chronic phase chronic myeloid leukemia (CML), with 71% of patients achieving durable complete remissions (CR). In relapsed acute myeloid leukemia, DLI led to durable CRs in 31% of patients; the rate was <20% in all other diseases. Achieving full donor chimerism and GVHD were predictive of CR. Grade II or higher acute or chronic GVHD occurred in 36 (43%) patients and contributed to death in 13 (16%). Even more patients, 33 (40%), died of their underlying malignancy, including 10 who developed active GVHD. In relapsed CML, most durable CRs occurred without clinically apparent GVHD, yet all responders achieved full donor chimerism, including 6 with coincident normal host hematopoiesis at the time of DLI. Thus, in CML, potent lymphohematopoietic graft-versus-host reactions occurred even in the absence of clinically apparent GVHD; this confirms the ability to dissociate these processes and argues against a leukemia-specific immunologic effect. DLI clearly has efficacy in the treatment of relapsed disease after allogeneic transplantation. However, with the exception of CML, most patients die of their underlying disease because of insufficient antitumor activity even with active GVHD.

Acute Disease↗
PubMed2006

Clinical outcome following autologous and allogeneic blood and marrow transplantation for relapsed diffuse large-cell non-Hodgkin's lymphoma.

High-dose chemotherapy followed by blood or marrow transplantation (BMT) is generally considered the best salvage option for patients with relapsed diffuse large-B-cell non-Hodgkin's lymphoma (DLCL). The relative roles for allogeneic and autologous BMT remain controversial. We reviewed the clinical outcome of 183 patients with relapsed DLCL who underwent BMT at Johns Hopkins University in 1985-2001. A total of 45 patients received T-cell-depleted HLA-matched allogeneic bone marrow (allo-BMT), and 138 patients received autologous marrow or peripheral blood stem cells (auto-BMT). The allo-BMT recipients had a higher proportion of patients with chemoresistant disease (P = .004) and had received more chemotherapy before BMT (P = .02). The auto-BMT recipients were older (P < .001) and were of more advanced-stage disease (P = .01). The 3-year overall survival (OS) was 23.7% (median survival, 129 days) after allo-BMT and 33.1% (median survival, 263 days), after auto-BMT (log-rank, P = .17). The 3-year OS for patients with sensitive disease was 51.9% after allo-BMT and 46.2% after auto-BMT (log-rank, P = .38). For patients with resistant disease, the 3-year OS was 12.1% after allo-BMT and 19.1% after auto-BMT (log rank, P = .08). In multivariate analysis, significant predictors of death were disease sensitivity (hazard rate [HR], 0.3; 95% confidence interval [CI] 0.2-04; P < .001), age >40 years (HR, 2.42; 95% CI, 1.7-3.4; P < .001), and stage at diagnosis (HR, 1.2; 95% CI, 1.0-1.4; P = .04). The 3-year event-free survival (EFS) for patients with sensitive disease was 52.7% after allo-BMT and 42.0% after auto-BMT (log-rank, P = .29). For patients with resistant disease, the 3-year EFS was 6.2% after allo-BMT and 19.4% after auto-BMT (log-rank, P = .1). The 3-year probability of relapse for chemosensitive patients was 30% after allo-BMT and 46.1% after auto-BMT (log-rank, P = .25). The 3-year relapse rate in patients with resistant disease was 75.0% after allo-BMT and 69.9% after auto-BMT (log-rank, P = .58). In multivariate analysis, only disease sensitivity status (HR, 0.4; 95% CI, 0.2-2.1; P < .001) and age >40 years (HR, 1.7; 95% CI, 1.1-2.9; P = .03) appear to have a significant impact on relapse. Transplant-related mortality (TRM) was the cause of death for 51.1% of allo-BMT recipients and 23.9% of auto-BMT recipients (P < .001). Mortality from lymphoma was 26.6% in allo-BMT recipients and 43.5% in auto-BMT recipients (P = .02). Auto-BMT and allo-BMT produced similar survival for patients with relapsed DLCL. For patients with sensitive disease, allo-BMT seemed to provide longer survival with less relapse; however, this was achieved at the cost of greater TRM.

Adolescent↗
PubMed2005

The paradox of response and survival in cancer therapeutics.

Although most patients with cancer respond to therapy, few are cured. Moreover, objective clinical responses to treatment often do not even translate into substantial improvements in overall survival. For example, patients with indolent lymphoma who achieved a complete remission with conventional-dose therapies in the prerituximab era did not experience a survival advantage over similar patients treated with a "watch and wait" approach. Several studies have also shown that neither the magnitude nor the kinetics of clinical response has an impact on survival in multiple myeloma. Recent data suggesting many malignancies arise from a rare population of cells that exclusively maintains the ability to self-renew and sustains the tumor (ie, "cancer stem cells") may help explain this paradox that response and survival are not always linked. Therapies that successfully eliminate the differentiated cancer cells characterizing the tumor may be ineffective against rare, biologically distinct cancer stem cells. New methods for assessing treatment efficacy must also be developed, as traditional response criteria measure tumor bulk and may not reflect changes in rare cancer stem cell populations. In this article, we discuss the evidence for cancer stem cells in hematologic malignancies and possible ways to begin targeting these cells and measuring clinical effectiveness of such treatment approaches.

Humans↗
PubMed2005

PIG-A mutations in normal hematopoiesis.

Paroxysmal nocturnal hemoglobinuria (PNH) is caused by phosphatidylinositol glycan-class A (PIG-A) mutations in hematopoietic stem cells (HSCs). PIG-A mutations have been found in granulocytes from most healthy individuals, suggesting that these spontaneous PIG-A mutations are important in the pathogenesis of PNH. It remains unclear if these PIG-A mutations have relevance to those found in PNH. We isolated CD34+ progenitors from 4 patients with PNH and 27 controls. The frequency of PIG-A mutant progenitors was determined by assaying for colony-forming cells (CFCs) in methylcellulose containing toxic doses of aerolysin (1 x 10(-9) M). Glycosylphosphatidylinositol (GPI)-anchored proteins serve as receptors for aerolysin; thus, PNH cells are resistant to aerolysin. The frequency of aerolysin resistant CFC was 14.7 +/- 4.0 x 10(-6) in the bone marrow of healthy donors and was 57.0 +/- 6.7 x 10(-6) from mobilized peripheral blood. DNA was extracted from individual day-14 aerolysin-resistant CFCs and the PIG-A gene was sequenced to determine clonality. Aerolysin-resistant CFCs from patients with PNH exhibited clonal PIG-A mutations. In contrast, PIG-A mutations in the CFCs from controls were polyclonal, and did not involve T cells. Our data confirm the finding that PIG-A mutations are relatively common in normal hematopoiesis; however, the finding suggests that these mutations occur in differentiated progenitors rather than HSCs.

Bacterial Toxins↗
PubMed2005

Outcomes of autologous and allogeneic blood or marrow transplantation for mantle cell lymphoma.

To evaluate high-dose therapy and autologous or allogeneic blood or marrow transplantation (BMT) for mantle cell lymphoma, patients receiving BMT for newly diagnosed or relapsed mantle cell lymphoma were identified through the registry at Johns Hopkins. The pathologic diagnostic criteria were reviewed, and details of the presentation, transplant procedure, and survival outcomes were determined. Fifty-eight patients were identified, of whom 64% underwent transplantation in first remission and 12% had primary induction failure. Nineteen patients (one third) received an allograft. Preparative regimens consisted of cyclophosphamide in combination with either busulfan or total body irradiation. On multiple regression analysis, transplantation after 1 or more relapses (hazard ratio, 2.98; P = .02), primary induction failure (hazard ratio, 5.39; P = .002), and allogeneic transplantation (hazard ratio, 3.03; P = .007) were associated with an inferior event-free survival (EFS). However, EFS curves were not statistically different for autologous and allogeneic BMT performed in first remission, with an estimated 3-year EFS approaching or equaling 70%. Primary induction failure and residual bone marrow involvement were the only statistically significant predictors of relapse on multiple regression analysis. At 3 years, the estimated EFS for the entire cohort after BMT was 51%, the probability of relapse was 31%, and the overall survival was 59%. The benefit of autologous or allogeneic BMT for mantle cell lymphoma is thus most apparent when transplantation is performed in first remission. Whether allogeneic BMT ultimately confers an advantage because of a graft-versus-lymphoma effect remains to be determined.

Adult↗
PubMed2005

High-dose therapy and blood or marrow transplantation for non-Hodgkin lymphoma with central nervous system involvement.

The role of autologous or allogeneic blood or marrow transplantation (BMT) remains undefined in patients with central nervous system (CNS) involvement by lymphoma. The records of all adult and pediatric non-Hodgkin lymphoma patients receiving BMT at Johns Hopkins from 1980 to 2003 were reviewed, and 37 patients were identified who had CNS involvement that was treated into remission by the time of BMT. The chief histologies were diffuse large B-cell lymphoma and T-cell lymphoblastic lymphoma/leukemia. Twenty-four percent received intrathecal chemotherapy alone, and 70% received intrathecal chemotherapy and CNS irradiation before BMT. The main preparative regimens were cyclophosphamide/total body irradiation and busulfan/cyclophosphamide. Forty-one percent received an allogeneic transplant. Lymphoma relapsed after BMT in 14 patients (38%), and at least 5 had documented or suspected CNS relapse. In multivariate models, age > or =18 years at diagnosis, resistant systemic disease, busulfan/cyclophosphamide conditioning, and lack of intrathecal consolidation after BMT were statistically significant predictors of inferior survival. The 5-year actuarial event-free survival was 36%, and overall survival was 39%. After BMT, long-term survival is thus achievable in a subset of patients with a history of treated CNS involvement by non-Hodgkin lymphoma. The survival rates are not dissimilar to those typically seen in other high-risk lymphoma patients undergoing BMT. These data suggest that patients with lymphomatous involvement of the CNS who achieve CNS remission should be offered BMT if it is otherwise indicated.

Adolescent↗
PubMed2005

Requirement for myeloid growth factors in the differentiation of acute promyelocytic leukaemia.

It is well known that the differentiation of acute promyelocytic leukaemia (APL) cells by all-trans-retinoic acid (ATRA) may be enhanced by myeloid growth factors, but the requirement for growth factors in this process is unclear. Our previous studies in multiple myeloma and non-APL acute myeloid leukaemia demonstrated that lineage-specific growth factors are required for the maximal activity of many pharmacologic differentiating agents in vitro. Thus, we studied whether the differentiation of APL is similarly dependent on growth factors. We found that the myeloid growth factors granulocyte colony-stimulating factor or granulocyte-macrophage colony-stimulating factor markedly increased the differentiation of NB4 cells or APL blasts from clinical samples treated with ATRA, arsenic trioxide (ATO), or bryostatin-1 as evidenced by the enhanced expression of myeloid surface antigens and the inhibition of clonogenic growth. Furthermore, myeloid growth factors were necessary for the differentiation of APL cells since the activity of each pharmacologic agent could be blocked by specific growth factor-neutralizing antibodies. Each differentiating agent was active only at concentrations that inhibited cell cycling, suggesting that this property is also required for differentiation. These data demonstrate that both pharmacologic differentiating agents and myeloid growth factors are required, but neither sufficient, for the differentiation of APL cells. The combined use of pharmacologic differentiating agents and growth factors may improve the clinical efficacy of differentiation therapy in APL.

Antineoplastic Agents↗
PubMed2005

Effects of imatinib and interferon on primitive chronic myeloid leukaemia progenitors.

Imatinib has impressive activity against chronic myeloid leukaemia (CML), but does not appear to completely eradicate the disease. Although responses to interferon-alpha (IFN) are slower and less dramatic than those to imatinib, they can be durable even after discontinuation of the drug. Unlike imatinib, the specific mechanisms responsible for IFN's clinical activity in CML are unknown. We found that IFN induced a G1 cell cycle arrest, as well as terminal differentiation, of the CML cell line KT-1 and CML CD34+ cells from clinical specimens. Myeloid growth factors augmented the antileukaemic activity of IFN, and neutralising antibodies directed against myeloid growth factors inhibited IFN's antileukaemic activity. We next directly compared the effects of imatinib and IFN against differentiated and primitive CML progenitors from newly-diagnosed patients. Although less active against CML granulocyte-macrophage colony forming units than imatinib, IFN was significantly more toxic to primitive CML progenitors responsible for the maintenance of long-term cultures. Imatinib and IFN appear to have divergent effects on CML progenitors at different stages of maturation, with imatinib more active against differentiated CML progenitors and IFN more active against primitive CML progenitors. The different target cells for these agents may explain the disparities in the kinetics and durability of their clinical responses. At least part of the clinical effect of IFN in CML appears to result from its ability to differentiate primitive CML progenitors.

Adult↗
PubMed2004

Association of Foxp3 regulatory gene expression with graft-versus-host disease.

Graft-versus-host disease (GVHD) is characterized by an impairment of mechanisms that underlie the development of immunologic tolerance. Although the cytokine storm associated with GVHD leads to expression of cell surface markers on both effector and regulatory T cells, regulatory CD4+ T cells that play an instrumental role in the maintenance of tolerance appear to uniquely express the Foxp3 transcriptional repressor. Foxp3 mRNA expression was significantly decreased in peripheral blood mononuclear cells from patients with either allogeneic GVHD or autologous GVHD compared with patients without GVHD. Expression of Foxp3 negatively correlated with the severity of GVHD but positively correlated with recent thymic emigrants. The results suggest that defective thymic function contributes to the impaired reconstitution of immune regulatory mechanisms following transplantation. The decrease in regulatory mechanisms after transplantation appears to provide an environment permissive to the development of GVHD.

Adolescent↗
PubMed2004

Role of NADPH oxidase in arsenic-induced reactive oxygen species formation and cytotoxicity in myeloid leukemia cells.

Arsenic has played a key medicinal role against a variety of ailments for several millennia, but during the past century its prominence has been displaced by modern therapeutics. Recently, attention has been drawn to arsenic by its dramatic clinical efficacy against acute promyelocytic leukemia. Although toxic reactive oxygen species (ROS) induced in cancer cells exposed to arsenic could mediate cancer cell death, how arsenic induces ROS remains undefined. Through the use of gene expression profiling, interference RNA, and genetically engineered cells, we report here that NADPH oxidase, an enzyme complex required for the normal antibacterial function of white blood cells, is the main target of arsenic-induced ROS production. Because NADPH oxidase enzyme activity can also be stimulated by phorbol myristate acetate, a synergism between arsenic and the clinically used phorbol myristate acetate analog, bryostatin 1, through enhanced ROS production can be expected. We show that this synergism exists, and that the use of very low doses of both arsenic and bryostatin 1 can effectively kill leukemic cells. Our findings pinpoint the arsenic target of ROS production and provide a conceptual basis for an anticancer regimen.

Antineoplastic Agents↗
PubMed2004

High-dose cyclophosphamide as salvage therapy for severe aplastic anemia.

OBJECTIVE: The treatment options for patients with aplastic anemia who do not respond to conventional immunosuppression are limited. The aim of this study was to evaluate high-dose cyclophosphamide in patients with refractory severe aplastic anemia (SAA). MATERIALS AND METHODS: We treated 17 SAA patients with high-dose cyclophosphamide (50 mg/kg/day for 4 consecutive days) who previously did not respond to one or more courses of immunosuppressive therapy. Median age was 31 years (range 6-58); median disease duration was 14 months (range 6-58), and 8 patients met criteria for very severe aplastic anemia (absolute neutrophil count <0.2 x 10(9)/L) at the time of treatment. RESULTS: At median follow-up of 29 months, 10 patients (59%) are alive. Nine patients (53%) achieved a drug-free remission after high-dose cyclophosphamide; 4 patients achieved a complete remission and 5 patients currently meet criteria for a partial remission but continue to improve. One nonresponder to high-dose cyclophosphamide developed paroxysmal nocturnal hemoglobinuria; another nonresponder developed a myelodysplastic syndrome. In responding patients, median time to 500 neutrophils was 54 days (range 35-119), median time to the last platelet transfusion was 99 days (range 51-751), and median time to the last red cell transfusion was 125 days (range 63-796). CONCLUSION: High-dose cyclophosphamide shows promise for salvaging patients with refractory SAA.

Adolescent↗
PubMed2004

Treatment options for chronic myeloid leukemia: imatinib versus interferon versus allogeneic transplant.

PURPOSE OF REVIEW: This review considers recent developments in the treatment of chronic myeloid leukemia with attention to current data evaluating the relative roles of imatinib mesylate, interferon-alpha, and allogeneic blood or marrow transplantation. Additionally, the review discusses advances in the basic understanding of the mechanisms by which these three different therapies function against chronic myeloid leukemia. RECENT FINDINGS: Long-term follow-up has found that interferon-alpha was able to produce complete cytogenetic remission in15 to 25% of patients, with some of these patients achieving a molecular remission. Some patients who achieve a complete cytogenetic remission also achieve long-term disease-free survival and possibly cure. Imatinib has produced remarkable hematologic and cytogenetic responses in newly treated and in interferon-alpha-refractory patients, yet there are no long-term survival data at this point. Some laboratory findings imply that imatinib may primarily affect mature chronic myeloid leukemia progenitors and not chronic myeloid leukemia stem cells, leaving doubt that the improved rate of complete cytogenetic remissions will result in increased overall survival. Other clonal cytogenetic abnormalities have also been reported in the Philadelphia chromosome-negative cells present in complete cytogenetic remissions to imatinib. The use of donor lymphocytes infusion (DLI) continues to treat relapsed chronic myeloid leukemia effectively after allogeneic blood or marrow transplantation whereas the use of nonmyeloablative therapy has effectively reduced transplant-related mortality. SUMMARY: Patients with chronic myeloid leukemia now have several potential treatment options from which to choose. Imatinib mesylate currently provides excellent hematologic and cytogenetic response rates with minimal toxicity. However, long-term data of efficacy is lacking. Emerging evidence that imatinib rarely leads to molecular complete remission and that many patients are still at risk of relapse and other clonal disorders is concerning and suggest the possibility that imatinib's early high response rates may not translate into survival advantage. Interferon-alpha continues to be effective therapy for many patients and, along with blood or marrow transplantation, is proved to prolong survival. The impacts of both are in part limited because of their toxicity profiles. Ongoing laboratory investigations and clinical trials remain paramount to providing the best treatment approach for our patients with chronic myeloid leukemia.

Antineoplastic Agents↗